Parental smoking, asthma, respiratory tract infections in childhood linked to adult OSA

Parental smoking, maternal asthma, and frequent lower respiratory tract infections before the age of 7 years are predictive of obstructive sleep apnoea (OSA) development during adulthood, suggests a study.

“While determination of their pathophysiological and any causal pathways require further research, these may be useful to flag the risk of OSA within clinical practice and create awareness and vigilance among at-risk groups,” the investigators said.

Probable OSA was significantly associated with maternal asthma (odds ratio [OR], 1.5, 95 percent confidence interval [CI], 1.1‒2.0), maternal smoking (OR, 1.2, 95 percent CI, 1.05‒1.5), childhood pleurisy/pneumonia (OR, 1.3, 95 percent CI, 1.04‒1.7), and frequent bronchitis (OR, 1.2, 95 percent CI, 1.01‒1.5). [Respirology 2024;29:63-70]

Likewise, parental smoking (OR, 1.3, 95 percent CI, 1.01‒1.6) and frequent asthma and bronchitis (OR, 1.3, 95 percent CI, 1.01‒1.9) correlated with probably OSA. These associations were consistent for Berlin questionnaire-defined OSA.

“Although these associations are longitudinal, it is difficult to determine if they are causal or mere predictors of OSA, given the current understanding of the pathophysiology of OSA,” the researchers said.

The following main pathophysiology pathways were widely accepted: an anatomically or functionally collapsible upper airway, poor upper airway dilator muscle responsiveness, high loop-gain of the respiratory system causing respiratory control instability, and low respiratory arousal threshold. [Am J Respir Crit Care Med 2013;188:996-1004]

“Nevertheless, it is difficult to directly link any of the risk factors that we detected to these pathophysiological pathways,” the researchers said. “For example, this current knowledge makes it difficult to theorize how maternal asthma would cause OSA in adult offspring.”

Inherited OSA

However, since OSA symptoms are hard to distinguish from those of nocturnal asthma, some of the maternal asthma could be maternal OSA and potentially signify a familial inheritance of OSA. [Respir Investig 2018;56:111-119]

In addition, maternal asthma could indicate abnormal airways, which could be inherited by offspring and contribute to adult OSA, according to the researchers. “However, the pathophysiology of this association should be explored in future research, and the studies of OSA epidemiology must explore maternal asthma as an alternative pathway to OSA.”

“Similarly, the pathophysiology of the association between early exposure to smoking and subsequent OSA remains to be sufficiently characterized,” they added.

On the other hand, several studies reported an association between passive smoking and childhood OSA. Such connection could be partially due to childhood OSA persisting until adulthood. [J Paediatr Child Health 2016;52:512-517; Laryngoscope 2015;125:241-247]

For the present study, the researchers obtained data from the population-based Tasmanian Longitudinal Health Study cohort (n=3,550), followed from the first to sixth decades of life. Potentially relevant childhood exposures, along with previously defined risk factor profiles, were collected from a parent-completed survey at age 7 years.

The researchers then gathered information on probably OSA (based on a STOP-Bang questionnaire cutoff ≥5), the primary outcome, when the participants were aged 53 years. Finally, they used logistic regression, with adjustments for potential confounders, to explore associations and the Berlin questionnaire to repeat analyses.